For all those who feared for the security and safety of personal messages being sent on the messaging App, WhatsApp, need to think twice now before sending out any such messages. According to an iOS researcher, WhatsApp retains and stores chat logs even after those chats have been deleted. He examined disk images taken from the most recent version of the app, and found that the software retains and stores a forensic trace of the chat logs even after a user has deleted them.

This supposedly creates an aggregation of information for anyone with physical access to the device. According to the research, the same data can also be recovered through a remote backup system. "Forensic trace is common among any application that uses SQLite, because SQLite by default does not vacuum databases on iOS (likely in an effort to prevent wear).

When a record is deleted, it is simply added to a 'free list', but free records do not get overwritten until later on," said the researcher. The problem is also somewhat similar to what PC users face when they delete an app. On a computer when you delete a file, it is not actually deleted. Only its attributes change and unless the sector where the data related to the file is stored on hard disk is overwritten or wiped clean, the "deleted" file could be retrieved.